def clone(self, target=_UNSET, via_column=_UNSET, name=_UNSET, bounds=_UNSET, **coax_kwargs):
kwargs = self.coax_kwargs
kwargs.update(coax_kwargs)
return How(
target=pdutils.coalesce(target, self.target, unset=_UNSET),
via_column=pdutils.coalesce(via_column, self.via_column, unset=_UNSET),
name=pdutils.coalesce(name, self._name, unset=_UNSET),
bounds=pdutils.coalesce(bounds, self.bounds, unset=_UNSET),
**kwargs,
)
def __repr__(self):
# NOTE: Do not change this to use any values that require additional arrays to be fetched!
num_chunks = pdutils.coalesce(self._matched_num_chunks, '?')
num_rows = pdutils.coalesce(self._matched_num_rows, '?')
csv_bytes = pdutils.coalesce(self._matched_csv_bytes, '?')
gz_bytes = pdutils.coalesce(self._matched_gz_bytes, '?')
parts = [
'chunks=%s' % (num_chunks,),
'rows=%s' % (strutils.format_number(num_rows, units=strutils.NUMBER_UNITS),),
'csv_bytes=%s' % (strutils.format_number(csv_bytes, units=strutils.SI_UNITS),),
'gz_bytes=%s' % (strutils.format_number(gz_bytes, units=strutils.SI_UNITS),),
]
return '<%s %r %s>' % (self.__class__.__name__, str(self.layout),
' '.join(x for x in parts if x))
def weighted_tqdm(items, weights=None, default_weight=0, total=None, **kwargs):
weights = pdutils.coalesce(weights, {})
total = total if not pdutils.is_empty(total) else (
sum(weights.values()) if weights else None)
if not weights and not default_weight:
yield from items
else:
with tqdm.tqdm(items, total=total, **kwargs) as tq:
for item in items:
yield item
weight = weights.get(item, default_weight)
tq.update(weight)
def allocate(csv_path_size, num_groups):
def insert_chunk(allocation, chunk):
# The smallest group is in groups[0].
group = allocation.groups.pop(0)
group_size = allocation.group_size.pop(0)
# Insert chunk into the smallest group in the correct sort order (smallest-largest chunks).
chunk_index = bisect.bisect_left(group.chunk_size, chunk.total_size)
group.chunks.insert(chunk_index, chunk)
group.chunk_size.insert(chunk_index, chunk.total_size)
# Reinsert group back into the allocation in the correct sort order (smallest-largest groups).
group_size = group_size + chunk.total_size
group_index = bisect.bisect_left(allocation.group_size, group_size)
allocation.groups.insert(group_index, group)
allocation.group_size.insert(group_index, group_size)
def optimize(allocation, threshold_percent=0.1):
while True:
diff_size = (allocation.group_size[-1] - allocation.group_size[0])
diff_percent = diff_size / (allocation.group_size[0] or diff_size)
if diff_percent <= threshold_percent:
break
# The largest group is in groups[-1].
largest_group = allocation.groups.pop(-1)
largest_group_size = allocation.group_size.pop(-1)
# Remove the largest chunk from the largest group.
largest_chunk = largest_group.chunks.pop(-1)
_ = largest_group.chunk_size.pop(-1)
# Re-insert the (formerly) largest_group back where it belongs.
# TODO(rob): insert_chunk pointlessly pops and re-inserts this again immediately.
largest_group_size = largest_group_size - largest_chunk.total_size
group_index = bisect.bisect_left(allocation.group_size,
largest_group_size)
allocation.groups.insert(group_index, largest_group)
allocation.group_size.insert(group_index, largest_group_size)
# Cut the largest chunk it into 2, and re-insert it.
head_chunk, bomb_chunk = largest_chunk.split()
insert_chunk(allocation=allocation, chunk=head_chunk)
insert_chunk(allocation=allocation, chunk=bomb_chunk)
# Create initial allocation of whole csv_path to groups.
num_groups = pdutils.coalesce(num_groups, NUM_CPUS)
allocation = Allocation(num_groups=num_groups, num_files=0)
for csv_path, csv_size in csv_path_size:
allocation.num_files += 1
csv_range = (0, csv_size)
chunk = Chunk(path=csv_path, size_range=csv_range, total_size=csv_size)
insert_chunk(allocation=allocation, chunk=chunk)
# Optimize groups by halving the largest chunk from the largest group.
optimize(allocation=allocation)
return allocation
def how_snug_labeler(how, layouts):
if how.target.labeler is not None:
# How.target has a labeler; may be LabelColumnTarget or GTypeLabelerTarget.
gtype = how.target.gtype
snug_step = how.target.labeler.step
snug_head = how.target.labeler.head
elif layouts:
# Extract the minimum value of step for this how across all layouts.
layout_gtypes = set()
layout_steps = set()
layout_heads = set()
for layout in layouts:
# Bind how to layout if possible; ignore this how if it can't be bound to layout (DROP).
# This will legitimately happen with the 2 layouts: ('lat_lng', 'year_month').
bound_how = how.bind_layout(layout=layout, errors_missing=lib_errors.DROP)
if bound_how is not None:
layout_gtypes.add(bound_how.target.gtype)
layout_steps.add(bound_how.target.labeler.step)
layout_heads.add(bound_how.target.labeler.head)
if len(layout_gtypes) > 1:
# Since a GTypeLabeler can label exactly one gtype, crash if we found multiple.
raise lib_errors.MultipleLabelColumnsError('found %d gtype matches in layouts: %r' %
(len(layout_gtypes), how))
if len(layout_gtypes) == 0:
# A spurious how clause (no matches with any layouts) also cannot create a labeler.
raise lib_errors.NoLabelColumnsError('found 0 gtype matches in layouts: %r' % (how,))
# We were provided with at least one layout; use min(step/head) for their labeler.
gtype = more_itertools.one(layout_gtypes)
snug_step = min(layout_steps)
snug_head = min(layout_heads)
else:
# With no provided layouts, how.target *must* have a gtype or we can't create a labeler.
gtype = how.target.gtype
snug_step = gtype.SANE_STEP
snug_head = pdutils.coalesce(gtype.HEAD, 0)
return gtype.labeler(step=snug_step, head=snug_head)
def balance(csv_paths,
out_dir,
num_groups=None,
max_workers=None,
relative_to=None,
symlink_ok=True,
csv_path_weights=None,
tqdm_desc='splitting'):
"""Computes an allocation and materializes it by splitting large files and symlinking others.
This function creates roughly equal-sized directories of csvs inside `out_dir`, in preparation for
processing them in parallel.
Confusingly, the `num_groups` parameter specifies the number of directories to allocate csvs into,
while the `max_workers` parameter specifies the number of workers to use while materializing the
allocation.
csv_paths: iterable of csv file paths
out_dir: non-existant directory to write new files into
num_groups: number of groups to allocate files into; default max_workers
max_workers: max number of parallel processes to run; default NUM_CPUS
relative_to: drop this prefix when writing files into out_dir; default csv_paths common prefix
symlink_ok: if True, symlinked non-split files into out_dir; if False, copy files
csv_path_weights {path: int}: optional mapping of path to allocation weight; default csv bytes
"""
max_workers = pdutils.coalesce(max_workers, NUM_CPUS)
num_groups = pdutils.coalesce(num_groups, max_workers)
# Read the number of rows in each csv file, and allocate them into num_groups.
csv_paths = tuple(csv_paths)
if csv_path_weights is None:
csv_path_weights = dict(csv_path_bytes(csv_paths=csv_paths))
logging.info('allocating csvs into %s groups...' % num_groups)
allocation = allocate(csv_path_size=tuple(csv_path_weights.items()),
num_groups=num_groups)
logging.info(allocation)
# Perform all required splits into their split_num directory.
relative_to = relative_to or os.path.commonpath(csv_paths)
file_splits = allocation.file_splits()
job_kw = {
'out_dir': str(out_dir),
'relative_to': str(relative_to),
'num_groups': num_groups,
'symlink_ok': symlink_ok
}
jobs = ((_write_groups, dict(path=str(path), file_splits=fs, **job_kw))
for path, fs in file_splits.items())
with tqdm.tqdm(desc=tqdm_desc,
total=sum(csv_path_weights.values()),
mininterval=1,
maxinterval=1) as tq:
with futures.ProcessPoolExecutor(max_workers=max_workers) as pool:
pending = set(
pool.submit(fn, **kw)
for fn, kw in itertools.islice(jobs, max_workers * 2))
while pending:
done, pending = futures.wait(
pending, return_when=futures.FIRST_COMPLETED)
for job in done:
finished_path = pathlib.Path(job.result())
tq.update(csv_path_weights[finished_path])
for fn, kw in itertools.islice(jobs, len(done)):
pending.add(pool.submit(fn, **kw))
return allocation
def clone(self, target=_UNSET, head_bombs=_UNSET):
return SequenceFilter(
target=pdutils.coalesce(target, self.target, unset=_UNSET),
head_bombs=pdutils.coalesce(head_bombs, self.head_bombs, unset=_UNSET),
)
def labeler(cls, step=None, head=None, depth=None):
if ((depth is not None and step is not None) or (depth is None and step is None)):
raise ValueError('must provide one of depth, step/head: depth=%r, step=%r' % (depth, step))
step = pdutils.coalesce(step, (depth is not None) and cls.depth_step(depth=depth))
head = pdutils.coalesce(head, cls.HEAD)
return super().labeler(step=step, head=head)
def depth_step(cls, depth, head=None, bomb=None): head = pdutils.coalesce(head, cls.HEAD) bomb = pdutils.coalesce(bomb, cls.BOMB, cls.TAIL) return (bomb - head) / 2**depth
def bucket(cls, val, step, head=None):
head = pdutils.coalesce(head, cls.HEAD, 0)
if is_scalar(val):
return cls._bucket_scalar(val, step=step, head=head)
return cls._bucket_pd(val, step=step, head=head)
